The disclosed embodiments relate to the field of structural rods.
More particularly the disclosed embodiments relate to a structural rod for the transmission of forces that is able to filter vibrations and that tolerates a failure of the structure of the rod.
In the field of mechanics, it is known how to use rods for numerous applications as mechanical linkage elements.
Although diverse applications: control rods, crank rods, anti-crash rods, reinforcing rods for floor or casing structures, engine force pickup rods, etc., rods in general are intended to pick up and transmit forces, essentially tensile and compressive forces between two points of a structure.
A structural rod such as the rod 100 shown exploded in FIG. 1 accordingly has essentially a rod body 101, generally cylindrical, and a fastening bearing 102, 103 at each end of the body, by which the rod is fastened to structural elements or to articles of equipment at the points for force absorption. Numerous embodiments of such rods exist.
The rod can be made, as shown in FIG. 1, with end bearings added to the rod by welding or cementing, for example, depending on the materials used.
The rod can also be made in one part, with the bearing being integrated in the body.
However, the different existing rods on the one hand are rigid in construction to transmit the forces expected with the minimum deformation, and on the other hand are no longer able to transmit the forces in case of the breakage of a part of the structure of the rod, of the body or of a bearing. In some applications these characteristics of rods are not satisfactory.
Thus in the transmission of forces in a significant vibrating environment, for example in the case of aircraft engine installations, the rigid rods have the fault of transmitting vibrations, and when they have to be attenuated, it is suitable to adjoin vibration-filtering elements in the mounting of the rod, such as elastomeric collars called “silent-bloc” at the points of juncture with the structure.
However, such added filtering elements prove to be insufficient and are the sources of problems of maintenance and require making compromises that are often difficult between the rigidity of fastening and their ability to filter vibrations.
In the case in which there is the risk of the rod breaking has to be taken into consideration, it is then necessary to provide multiple possible pathways for the forces by multiplying the number of rods, which is not without its consequences on the complexity of the installation, on weight, and on costs.